Metal article deforming method and apparatus therefor



1956 F. F. MAUTONE 2,7 9,

METAL ARTICLE DEF ORMING METHOD AND APPARATUS THEREFOR Filed Aug. 30. 1952 Unitid tes ntb METAL ARTICLE DEF'ORMING METHOD AND APPARATUS THEREFOR Francesco F. Mautone, Chicago, Ill., assiguor to Admiral Corporation, Chicago, Ill a corporation of Delaware Application August 30, 1952, Serial No. 307,329

3 Claims. (Cl. 29-522) This invention relates to method and apparatus for de forming metal articles, and in particular to metal articles such as studs or screws, when extending through other parts to which said articles are captivated, although the invention is not limited to studs and screws.

In the process of captivating screws in threaded assembly with other parts, previous processes involved upsetting or splitting the ends of the screws while they were in threaded assembly with mating parts. This process involved use of power presses equipped with special dies, the same being expensive to manufacture and involving painstaking manual effort before these machines were in readiness for performing the captivating operation. Even after the tools were provided, the previous methods added greatlyto the cost of the furnished article as well as inquite brittle.

By the present invention apparatus is provided by which the captivating method is performed on a simple drill press, a machine which is more common, in the average factory, than a power press. Furthermore, the novel apparatus may be installed on a drill press in a minimum of time, is simple of construction, easy of manipulation when installed and is safer for an operator thereof than is a punch press.

Referring now to the drawings:

Fig. 1 is a top plan view of a terminal block in which the invention is incorporated;

Fig. 2 is a fragmentary vertical sectional view of the novel apparatus, partly in elevational, the terminal block being in transverse section;

Fig. 3 is a fragmentary section of the terminal block as it is portrayed in Fig. 2, but after the captivating operation has been performed on one of the screws thereof; and

Fig. 4 is a plan view of the parts shown in Fig. 3.

The significance of the present invention can best be understood on reference to Fig. 1 wherein a terminal block for electric current bearing wires is indicated in its entirety by the reference character 6. It comprises an elongated base 7 of some suitable insulating material such as Bakelite which is formed to provide a plurality of fins or walls 8 extending transversely of the base from the plane of the lower side thereof to an elevation well above the heads of pairs of terminal screws 9. Metal coupling strips 11, conveniently anchored to the base between the fins, are formed to provide hollow bosses 12 extending into holes 13 in the base for rigid connection therewith. The bosses are threaded for the reception of screws 9.

When the screws 9 are initially associated with the strips 11 their threaded portions are, of course, of substantially uniform diameter throughout their lengths thereby enabling their removal to be effected. Since it is desirable to prevent their complete removal, their free ends, that is, their ends remote from their heads, are swedged laterally. The means by which this is carried out is indicated in Fig. 2 wherein a rigid support or anvil of convenient cross section is indicated by the character creased the breakage because the insulating material is t 14. It is rigidly mounted on the platform 16 of a drill press in coaxial relationship to a chuck 18 thereof, movable vertically above the anvil. At its upper end, the anvil 14 has a recess 15 of diameter slightly greater than the head of the screws 9 to receive the heads. The free end of each of the screws is thus accessible to a spinning tool 17 operatively secured in the chuck.

The structure of the tool 17 is cylindrical, particularly on either side of a region of enlarged diameter 19, intermediate its ends, the upper portion providing a support shank 21 for engagement by the chuck, a shoulder 20, as a stop surface to regulate the position of a shank in the chuck and a guide shank portion 22 but slightly smaller diametrically than any one of the holes 13 so that when the chuck is lowered, there is a guiding or centering influence exerted by the tool on the block 6 to bring one of the screws into substantial axial relationship with the tool 17. At its lower end, the tool is recessed as at 23 to receive the free end of one of the screws 9, since the extremity of the screws may closely approach the bottom of the block 6. Additionally, the tool 17 is formed, eccentric of its axis, with a bore 24 extending from its upper end to and opening into the recess 23 so that a ball 26, of hardness greater than the composition of the screws 9, may be housed for engagement with said screw when the spindle 18 is lowered. To prevent loss of the ball from its support when the spindle is raised, the recess may be deformed slightly at 27 at the lower end of the bore 24 without interfering with extension of a portion of the ball into the recess 23 nor interfering with freedom of adjustment of the ball in a direction longitudinally of the tool. The upper end of the bore 24 is threaded to receive a set screw 28 between which and the ball 26 is a spacer pin 29 for conveying vertical ad justment of the set screw to the ball both for initial adjustment thereof with respect to the end of shank 22 and also to compensate for wear of said ball. I also contemplate that the ball 26 could be eliminated and a rounded end provided on the pin 29 which, if it was hardened and polished, would also be effective to carry out the deformation operations. In this instance, it would slide rather than roll.

Although I have indicated the tool 17 as movable with respect to a rigid and stationary support 14, I also contemplate more specialized yet simpler equipment com prising a counterpart of the tool journaled in a support for rotary motion only and a counterpart of the support 14 which is movable vertically to carry the work into engagement with the tool. At this point it is also noteworthy that the tool 17 has been successfully used in the chuck of a hand drill for deforming the screws.

In operation, the terminal block is held in inverted position over the anvil 14 and the head of each of the screws 9 severally brought into engagement with the bottom of recess 15, to roughly locate the block 6 with respect to the tool 17. Then the chuck is lowered and consequent journaled relationship established between the shank 22 and hole 13 to center the screw 9 with respect to the tool 17. This provides for engagement of the sphere 26 with the extremity of screw 9 at a region between the axis and periphery of said screw. During its pressure engagement with the screw 9, the ball may roll in the course through which it is carried and in so doing creates a track 31 displacing the metal outwardly to pro vide an end diameter greater than the diameter of the threaded interior of boss 12. The screw can be adjusted longitudinally only to an extent permitted by cooperation of the mushroomed portion 32 and a washer 33 adjacent the head.

By the novel tool 17, together with the: anvil 14 means has been provided by which screws can be captivated without the sudden movement of a die as when carried by apunch press with consequent danger to the operator of such a machine.- Furthermore, the novel mechanism affords. meansfor .etfectively captivating screws with less deformation than is necessary when the prior method of splitting the screws end is adopted, the latter producing sharp lateral extremities. Also, there is little possibility of'bending the screw as when its end issplit by a power press or of deforming the screw threads and making the same either too tight or completely inoperative.

Although I have shown my invention as being used in connection with the captivation 0f screws in a terminal strip, it will be apparent that the method and apparatus is equally useful in performing the same operation on screws in other places,

While I have shown my invention in an embodiment thereof, I am aware that extensive other departures may be made therefrom without departing from the spirit or scope of the invention.

I claim:

1. A tool for spinning the end of a screw to deform the same at its end comprising an elongated body having one end for engagement in a chuck or the like, the other end of said tool being formed with a recess for the reception of the end of a screw, means for engaging and deforming the end of the screw to upset the end thereof comprising a hard ball, said bodybeing formed with a longitudinally extending through bore eccentric to the axis of the tool and the wall of the bore being restricted at said other end thereof, said bore receiving the ball and the restricted end retaining the ball and being of such a diameter that the ball extends into the bore in a position for engagement withthe screw at a point inwardly of said recess, an abutment member in the bore engaging the ball and holding said ball in position and screw means in saidbore to hold said member in place.

2. A tool for spinning the end of a screw to mushroom the same at its end comprising an elongated body having one end for engagement in a chuck or the like, the other 7 end of said tool being formed with a recess for the reception of the end of a screw, means for engaging and spinning theend of the screw to upset theeud thereof comprising a hard ball, said body being formed with a bore eccentric of the axis of the tool and being restricted at said other end thereof to retain the ball in the bore and provide for its extension in a position for engagement with the screw at a point inwardly of said recess, and an abutment member movably disposed in the bore engaging the ball and screw means in said bore engaging the end of said member opposite to said ball engaging end to hold said member in pressure engagement with said ball.

3. Method of assembling and adjustably securing a screw within an aperture with a restricted portion comprising assembling only the threaded portion of said screw within said aperture with the end of said threaded portion within the unrestricted portion of the aperture, resting the head of the screw on an anvil adjacent said restricted portion while the threaded portion is within said unrestricted portionof the aperture, subjecting the extremity of said threaded portion of the screw to gradual application of force by a sphere rotating and eccentrically moving while surrounded by a circular recess for the reception of said extremity to gradually form an arcuate groove in said extremity and simultaneously flaring the perimeter of said extremity until it is deformed to a diameter substantially greater than the restricted portion and smaller than said unrestricted portionof the aperture. 

